March 25, 2010

Worm Keeping for Beginners

A year and a half ago, my partner and I went to a workshop on vermicomposting. We came home with a bin, worms, and heads full of knowledge. We were prepared. We were excited. We were in for months of fruit fly invasions, swampy smells seeping up from our basement, and various other surprises. Like slugs. And slimy mould.

But we survived and so did the worms. Those little critter are so prolific that last month I gave away 7 litres of them to good homes. I also gave lots of advice. Here are the basics for starting your own worm compost bin.

Reasons to Vermicompost
  • It can be done anywhere as the worms don't take up much space.
  • Valuable resources are kept out of the landfill and it helps reduce greenhouse gases.
  • Your garden will love you!
  • Worms are quiet, low maintenance and actually quite interesting.
  • Worms work fast, so you'll have compost in no time.

Feeding Your Worms
Red Wrigglers will eat most kitchen waste. Any fruit or vegetable waste that you generate during food preparation can be used, such a s carrots, lettuce, cabbage, celery, apples, banana peels, and tea leaves and bags. Citrus peels, coffee grounds and tomatoes can be added, but only in moderation, as they will acidify the bedding. Adding dried crushed eggshells will help to control acidity, and will also provide the worms with valuable nutrition. The worms are even interested in very small amounts of such leftovers as spaghetti, grain cereal, bread and pancakes.

NOTE: Avoid feeding your worms meat, fish, bones, dairy products and oily foods. These foods will cause odours and attract unwanted insects. Garlic, salt, vinegar and spicy leftovers should not be added, nor should large quantities of onions. These foods can hurt the worms.

Climate and Temperature
Red Wrigglers prefer temperatures between 15 – 25°C. Lower than 10°C or higher than 30°C can result in death. I've been told that red wrigglers can be added to your outdoor compost bin, but I haven't tried this yet. They will apparently move to the areas of the bin that aren't too hot, though in some climates, I think the temperature would be too much for them. They will not survive the winter in cold climates, but their eggs should, and they will hatch baby worms the next spring.

It is necessary to provide a bedding for the worms to live in, and to bury food waste in. Suitable bedding materials are shredded newspaper and cardboard, shredded fall leaves, chopped up straw and other dead plants, seaweed, sawdust, compost and aged manure. I usually use either shredded newspaper or chopped up cardboard egg cartons, since we have both around the house. I don't use glossy magazine or flyer paper, though I'm not sure if that is really a no-no, or if it just seems more toxic to me.

Divide and Harvest: Shift all the old bedding, castings and worms in the bin to one side. Add fresh bedding to the other side. Bury fresh scraps in the new bedding for a few weeks, and keep the new bedding covered. Leave the old bedding uncovered. Check after a week or two; the worms will have migrated to the fresh bedding. Harvest the compost then fill the empty side with fresh bedding. This only works well if you do it regularly. If you get too much compost in the bin, the next method works better.

Dump and Hand Sort: Place a large sheet of plastic on the floor or on a table. Dump the entire contents of the bin onto the sheet. Shape the compost into cone-shaped mounds. Shine a bright light above the mounds; this will drive the worms toward the bottom interior of each mound. Wait 5-10 minutes then gently scrape off the layers of compost until all you have left is worms. (You may see tiny, lemon-shaped cocoons; these contain baby worms, so be sure to add them to the new bin.)

Smells: When the lid is on, a well-maintained bin is odorless; when opened, it should have little smell - if any, the smell is earthy. Worms require gaseous oxygen. Oxygen can be provided by airholes in the bin, occasional stirring of bin contents, and removal of some bin contents if they become too deep or too wet. If decomposition becomes anaerobic from excess feedstock added to the bin in wet conditions; or layers of food waste have become too deep, the bin will begin to smell like ammonia.

Moisture: If bin is too wet, the smelly, excess waste water must be removed and the bin returned to a normal moisture level. To do this, first reduce addition of food scraps with a high moisture content and second, add fresh, dry bedding such as shredded newspaper to your bin, mixing it in well. If the bin is too dry (not a common problem), then lightly moisten the bedding before adding it. To control both moisture levels and fruit flies, I freeze everything first, then thaw it, drain off the moisture, and then add it to the bin. We also have our bin set up on and angle, and drain the compost tea from the one corner using a turkey baster. If you are just setting up a bin, then get two containers. Drill holes in the bottom of one, and then set it into the other. Make sure it is a tight fit, or you will have fruit flies.

Pests:  Fruit flies breed in the bins if fruit and vegetable waste is not thoroughly covered with bedding. This problem can be avoided by thoroughly covering the waste by at least 2 inches of bedding. Maintaining the correct pH (close to netural) and water content of the bin (just enough water so that the compost is like a squeezed out sponge) can help avoid these pests as well. Slugs can also be a problem if outdoor leaves or grass clippings are added to the bin. Slugs found in the bin can be picked out and disposed of. Do this regularly until no slugs appear. To avoid slugs, do not use outdoor materials.

Worms escaping:  Worms generally stay in the bin, but may try to leave the bin when first introduced, or often after a rainstorm when outside humidity is high. Maintaining adequate conditions in the worm bin and putting a light over the bin when first introducing worms should eliminate this problem.

Preventing die-off: Worms will regulate their own population according to the conditions of their environment. These conditions include space, moisture, pH, temperature, bedding material, and amount of food, among others. A typical household worm bin might start out with one pound of worms (approximately 1,000 adults), which will soon multiply to 2,000–3,000 if conditions are good. Conversely, if one or more of the above conditions are unacceptable, the worms may “crawl” (leave the bin) or die off. Maintaining adequate moisture and harvesting the compost before the bin gets too full are the most important things to do to prevent die-off.


Melissa said...

This was a great article. We were just watching something on vermicomposting and I was wondering how big of a deal it would be for us to get into. You make it sound simple enough. Thanks for sharing your insights.

mainely stitching said...

This is something I'd like to do, but my better half is a little freaked by the idea. Thanks for this article - it may be just the thing to reassure him. :)

this single spark said...

Glad you enjoyed the post! It is really easy, once you get going. I think the biggest thing is to be regular about it. Feed them regularly, empty the finished compost out regularly... And I'm not talking a big time commitment. We feed the worms about once a week, harvest about one a month.

I live in Canada, so my garden still has snow on it. I just chuck the compost on top of the snow, and dig it in in the spring (which should be any day now!). I'm hoping for an amazing harvest this year.

And finally, I work in an academic library, so the guilt is getting to me. Must. Site. Sources.

I took a lot of the information from the handout we got at the vermicomposting workshop that started it all. But surfing around the web to find where I got the troubleshooting info, I discovered that my handout had some word-for-word paragraphs from the Wikipedia entry on vermicomposting. I can't say for sure where the rest of the info came from (other than my head), but there are tons of resources on the net. Happy surfing!

lisa s said...

fantastic step by step.... if only i could get past my creepy crawly aversion to a pile of worms... :D

Kerstin Svendsen said...

awesome post! (and lisa, i am the same way, much to my disappointment.) i went to a class on worm composting with some friends. the teacher said he found himself planning his meals according to what he thought the worms might like! his diet changed because of the worms. he loved em. funny. anyhow, it's great to have the info in writing.

Tracy said...

we are trying to do this at the girls school - but without much luck. i think it is the being regular part that has us failing. this info will help! thanks! xo

Di said...

Great info! We have been successfully worm farming for a couple of years now, using a three tray system- the bottom and middle one have well composted stuff in it, and the top one is where I add new food. When the top one is getting full, it's time to rotate them and empty out the bottom one- I leave the top off for a while to encourage them to migrate down, and then add some water to the castings before adding to the veggie patch as a slurry/topping where needed. The worm tea (juice/wee/liquid, whatever you want to call it) collects in the bottom of the unit, where I can drain it off regularly to water down as a liquid fertilizer.

We have also found our worms are fine all year around outside (in a shaded, sheltered spot) in Melbourne Australia- temp range is about 5 to 35 deg C, although the worms were killed off by the scorching high 40's days we had last summer.